Double-draft arrangement for spinning flax, jute, and similar fiber



n 24 193 G. P. wERsHmm 1,166 864 DOUBLE DRAFT ARRANGEMENT FOR SPINNING FLAX, JUTE, AND SIMILAR FIBER Filed June 5, 1929 GEO/m B MRsm/w/v 3mm ["1 as m 7). liw' Mp- ATTORNEY Patented June 24, 1930 UNITED STATES PATENT orricr.

GEORG P. WERSHININ, 0F .MOSCOW, UNION OF SOVIET SOCIA-LIST REPUBLICS DOUBLE-DRAFT ARRANGEMENT FOR SPINNING FLAX, JU'IE, AND SIMILAR FIBER Application filed June 5, 1929, Serial No. 368,510, and in the Union of Soviet Socialist Republics April My invention relates to double draft arrangement for spinning flax, jute and similar .fiber, and has a particular reference to methods and apparatus for producing draft by two independent means, when preparing strands .of fibrous material, such as flax, jute, hemp, etc., which are characterized by a long staple or fiber.

The drawing and combing operations are of a great importance in preparing fibrous materials for spinning, as they determine the fineness and parallelism of the fiber or lint in strands (laps, slivers) of such materials.

The draft, which represents relative slid.- ing of individual fibers with corresponding increase in length of the strand and its reduction in thickness, is determined as the ratio between the peripheral velocities of feeding (receiving) and drawing (delivering) rolls of preparatory, drawing or spinning (and roving) frames.

In order to prevent the tearing of individual fibers by the rolls, the distance between them must be made longer than the fiber itself. Therefore for materials with an especially long fiber, such as mentioned above, this distance becomes so large, that the material would develop considerable sag if not supported between the rolls.

Such support is afforded by a row of sharp pins or needles which enter between the fibers and move with them between the rolls. Due to a certain degree of friction between such gill pins and the fiber, the latter may be retarded or accelerated in its movement from one set of rolls to the other. At the same time this friction limits the effect of the draft produced by the drawing rolls to only a certain portion of the sliver, nearer these rolls.

I found, however, that it is possible to proportion the relative speeds of the gill pins and rolls so, that the gill pins themselves will produce a certain draft for the first portion of the sliver between the rolls, the rest of the sliver being drawn by the drawing rolls.

WVith this arrangement I obtain, therefore, a double draft, or'two independent drafts in a single space between two pairs of rolls. The result is that the fiber is subjected to a more uniform tension, and for a given draft the strain on individual fibers is considerably reduced, thereby causing less damage to the fiber and, even, permitting to increase the draft for a single drawing operation. This also insures a greater uniformity of the product and its better quality.

My invention is more fully described in the accompanying specification and drawing in which Fig. l is a diagram of relative speeds of the gill pins and the fibers: Fig. 2 is a diagrammatic view of a drawing device with a single draft; Fig. 3 is a diagram of speeds for adouble draft, and Fig. 4 is adiagram matic view-of a device with a double draft.

My device comprises feed rolls 1 between which a strand of a fibrous material 2 is clamped. At a certain distance a B, determined the length of fiber, a pair of drawing rolls 3 and 4 is located. The roll 4 is made substantially heavy-or provided with suitable tensioning devices (not shown) in order to prevent slippage of the fibers'between'this roll and the roll 3.

A row of sharp needles or gill pins 5 is arranged between the feed and drawing rolls. These needles are mounted .in blocks-(informing a continuous band. This .bandvslides in special upper guides 7 attached to the frame of the machine. Corresponding lower guides 8 are provided for the return movement of the band with gill pins.

The gill pins are usually given a speed of movement comparable to the peripheral speed of the feed rolls, or slightly in excess (by about 1 5%). Therefore the strand of fiber.2 moves with the gill pins without receiving any draft until the friction of the fiber between the pins is overcome by the drawing force rolls 3 and l. This somewhere in the and drawing rolls, asshown in F ig. 2.

The relative velocities Fare represented diagrammatically in Fig. 1. Here the abscissa AB represents the distance between the centers of the two pairs of rolls,

exerted by the drawing eifect becomes noticeable middle between the feed 9 and the speeds are plotted on the ordinata A-C. The line D-E corresponds to the constant peripheral speed of the feed rolls 1, and the line CF to the correspondingly greater peripheral velocity of the draft rolls 3 and 4:. The curve GI-I will then represent corresponding speeds at different points of the strand 2.

The diagram clearly shows that during the first part of the travel, up to the point M, the strand of fibers moves almost at the same speed as the needles or pins 5 di lfering but little from the peripheral speed of the feed rolls 1. Beginning with the point M the pulling effect of the higher speed of the drawing rolls 3 and a: becomes apparent, causing a rapid increase in the speed of the fiber in relation to the speed of the gill pins, as shown by the steeply rising curve G-I Such rapid stretchin or drawing of the fiber is dangerous as it may tear the individual fibers and otherwise damage them, causing also uneven distribution of fibers in the stretched thin strand.

Much better results are obtained if the needles are moved with a greater speed than the peripheral speed of the feed rolls 1, as shown in the diagram of Fig. 3. The speed of the needles is indicated with the line D-E. The speed of the strand of fiber is indicated with a curve K--L. It begins at the point K, corresponding to the peripheral velocity of the feed rolls 1, considerably below the speed of the needles. The needles will drag by friction the fibers until their velocities become equal at the point N. From this point the speed of the fibers will gradually increase to higher values under pulling action'of the drawing rolls 3 and 4.

It is easy to see that the total amount of draft is the same in both cases as indicated by the vertical distance between the points Gr and C and K and C, but in the second case the rise in speed is much more gradual, being result of two difierent causes: at first, by the action of the needles, and at the end, by the drawing rolls. IVith such double draft it becomes possible to use a greater amount of stretching or drawing between the rolls, and the product becomes stretched more uniformly, giving a better grade of fiber. The fiber becomes more thoroughly and evenly combed.

In practical applications of my method it is possible simply to reduce the velocity of the feed rolls below the speed of the needles (for instance, two or three times). The speeds of the other parts of the machine then neednot be changed.

It is evident, however, may be applied in a variety modifications, by following the main principles of speed distribution, as explained above.

that this method of practical \Vith my double draft the strain on the parts of the machine is greatly reduced, so that the drawing rolls work smoothly, without jerks or vibrations, the fiber or lint does not become wound on the rolls, and the shafts do not become overheated in the bearings. This, of course, tends to increase the life of the apparatus and to reduce its maintenance cost.

I claim as my invention:

1. A process of a double draft for flax, jute and the like on preparatory and spinning machines, consisting in carrying said flax or jute on combing needles between feed rolls and drawing rolls at a speed. greater than the peripheral speed of said feed rolls by at least and correspondingly slower than the peripheral speed of said drawing rolls. 7

2. In a double draft arrangement for flax,

jute and similar fibrous material, the combination with feed rolls for said material, drawing rolls for said material, and a plurailty of combing needles between said feed and drawing rolls, adapted to support said material between said feed and drawing rolls and being arranged to move from said feed to said drawing rolls at a speed greater than the peripheral speed of said feed rolls by at least 1-7 100% and correspondingly slower than the peripheral speed of said drawing rolls.

In testimony whereof I afiix my signature.

GEORG P. IVERSHININ.

said needles being 

